That the Messenger of Allah ﷺ said: "Whoever acquires a dog - with the exception of a dog to guard livestock, a hunting dog, or a farm dog - each day a Qirat is deducted from his reward." (Using translation from Tirmidhī 1490)
أَنَّ النَّبِيَّ ﷺ قَالَ مَنِ اتَّخَذَ كَلْبًا إِلَّا كَلْبَ مَاشِيَةٍ أَوْ صَيْدٍ انْتَقَصَ مِنْ أَجْرِهِ كُلَّ يَوْمٍ قِيرَاطَانِ